Describe the situation with the mad dog. How does this change the children's perception of Atticus?

One day a dog named Tim Johnson appears in the neighborhood, down the street from the Finch house. He looks strange appearance and walks slowly, with a twitch. The children tell Calpurnia, who takes one look at the dog and immediately calls Atticus to tell him that there's a rabid dog in the neighborhood. Next Calpurnia gets the town operator to call everyone in the neighborhood to warn them. She even runs over to the Radley house and yells a warning to them. Atticus and the sheriff, Heck Tate, drive up, and the sheriff gives Atticus the gun. The dog is so close to the Radley house that a stray bullet might go into the building. Atticus reluctantly takes aim and shoots the dog. The dog crumples into a heap. Jem is dumbstruck with the accuracy of his father's shot. Miss Maudie tells the children that their father used to be known as "One-Shot Finch," the best dead-shot in the county. She says he doesn't shoot unless he has to, because he feels that when he holds a gun, God has given him an unfair advantage over living beings. Scout wants to tell everyone in school about the incident, but Jem tells her not to. Jem explains that he wouldn't care if Atticus "couldn't do a blessed thing," because Atticus is a gentleman.